Potassium chloride detailed information
You don't need to be Editor-In-Chief to add or edit content to WikiDoc. You can begin to add to or edit text on this WikiDoc page by clicking on the edit button at the top of this page. Next enter or edit the information that you would like to appear here. Once you are done editing, scroll down and click the Save page button at the bottom of the page.
| Potassium chloride detailed information | |
|---|---|
| |
| |
| Other names | sylvite (mineral form); muriate of potash |
| Identifiers | |
| CAS number | |
| Properties | |
| Molecular formula | KCl |
| Molar mass | 74.551 g/mol |
| Appearance | white crystalline solid |
| Density | 1.987 g/cm3 |
| Melting point |
776 °C |
| Solubility in water | 28.1 g/100 cm³ (0°C); |
| Related Compounds | |
| Other anions | potassium fluoride; potassium bromide; potassium iodide |
| Other cations | sodium chloride;rubidium chloride |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references | |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Phone:617-525-6884
Please Take Over This Page and Apply to be Editor-In-Chief for this topic: There can be one or more than one Editor-In-Chief. You may also apply to be an Associate Editor-In-Chief of one of the subtopics below. Please mail us [2] to indicate your interest in serving either as an Editor-In-Chief of the entire topic or as an Associate Editor-In-Chief for a subtopic. Please be sure to attach your CV and or biographical sketch.
The chemical compound potassium chloride (KCl) is a metal halide composed of potassium and chlorine. In its pure state it is odorless. It has a white or colorless vitreous crystal, with a crystal structure that cleaves easily in three directions. Potassium chloride crystals are either simple cubic or face-centered cubic depending on what atoms are involved. If only potassium or chlorine atoms are considered, then the structured is face-centered cubic. However, both atoms form a crystal with a simple cubic structure: x-ray diffraction analysis will yield a simple cubic structure. Potassium chloride is also commonly known as "Muriate of Potash". Potash varies in color from pink or red to white depending on the mining and recovery process used. White potash, sometimes referred to as soluble potash, is usually higher in analysis and is used primarily for making liquid starter fertilizers. KCl is used in medicine, scientific applications, food processing and in judicial execution through lethal injection. It occurs naturally as the mineral sylvite and in combination with sodium chloride as sylvinite.
Chemical properties
Potassium chloride can react as a source of chloride ion. As with any other soluble ionic chloride, it will precipitate insoluble chloride salts when added to a solution of an appropriate metal ion:
Although potassium is more electropositive than sodium, KCl can be reduced to the metal by reaction with metallic sodium at 850 °C because the potassium is removed by distillation (see Le Chatelier's principle):
- KCl(l) + Na(l) ⇌ NaCl(l) + K(g)
This method is the main method for producing metallic potassium. Electrolysis (used for sodium) fails because of the high solubility of potassium in molten KCl.
As with other compounds containing potassium, KCl in powdered form gives a lilac flame test result.
Biological/Medical properties
Potassium is vital in the human body and oral potassium chloride is the common means to replenish it, although it can also be diluted and given intravenously (of course, in concentrations much lower than those used in executions). It can be used as a salt substitute for food, but due to its weak, bitter, unsalty flavor, it is usually mixed with regular salt, sodium chloride, for this purpose to improve the taste (for example, in Morton® Lite Salt [3]). Medically it is used in the treatment of hypokalemia and associated conditions, for digitalis poisoning, and as an electrolyte replenisher. Brand names include K-Dur®, Klor-Con®, Micro-K®, and Kaon Cl®. Side effects can include gastrointestinal discomfort including nausea and vomiting, diarrhea and bleeding of the gut. Overdoses cause hyperkalemia which can lead to paresthesia, cardiac conduction blocks, fibrillation, arrhythmias, and sclerosis.
Physical properties
Potassium chloride has a crystalline structure like many other salts. Structure: face-centered cubic. Lattice Constant: roughly 6.3 angstroms.
In chemistry and physics it is a very commonly used as a standard, for example as a calibration standard solution in measuring electrical conductivity of (ionic) solutions, since carefully prepared KCl solutions have well-reproducible and well-repeatable measurable properties.
| Solubility of KCl in various solvents (g KCl / 100 g of solvent at 25 °C) | |
|---|---|
| H2O | 36 |
| Liquid ammonia | 0.04 |
| Liquid sulfur dioxide | 0.041 |
| Methanol | 0.53 |
| Formic acid | 19.2 |
| Sulfolane | 0.004 |
| Acetonitrile | 0.0024 |
| Acetone | 0.000091 |
| Formamide | 6.2 |
| Acetamide | 2.45 |
| Dimethylformamide | 0.017 - 0.05 |
| Reference: Burgess, J. Metal Ions in Solution (Ellis Horwood, New York, 1978) ISBN 0-85312-027-7 | |
Precautions
Orally it is toxic in excess; the LD50 is around 2500 mg/kg (meaning that a person weighing 75 kg (165 lb) would have to consume about 190 g (6.7 oz); regular salt is about as toxic). Intravenously this is reduced to just over 100 mg/kg but of more concern are its severe effects on cardiac muscles; high doses can cause cardiac arrest and rapid death. A massive overdose of intravenous potassium chloride is used to stop the heart in execution by lethal injection.
References
- Handbook of Chemistry and Physics, 71st edition, CRC Press, Ann Arbor, Michigan, 1990.
- N. N. Greenwood, A. Earnshaw, Chemistry of the Elements, Pergamon Press, 1984. ISBN 0-08-022057-6
cs:Chlorid draselný de:Kaliumchloridfr:Chlorure de potassium gl:Cloruro de potasio it:Cloruro di potassio lv:Kālija hlorīds lt:Kalio chloridas hu:Kálium-klorid nl:Kaliumchloride ja:塩化カリウム no:Kaliumkloridsr:Калијум хлорид fi:Kaliumkloridi sv:Kaliumklorid uk:Хлорид калію
Acknowledgement and Attribution Regarding Sources of Content
Some of the initial content on this page may be incorporated in part from copyleft sources in the public domain including wikis such as Wikipedia and AskDrWiki. Drug information for patients came from the The National Library of Medicine. Infectious disease information may have come from the Centers for Disease Control (CDC). Differential Diagnoses are drawn from clinicians as well as an amalgamation of 3 sources: 1.The Disease Database; 2. Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:3; 3. Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:7 .
